1. WATER IN THE WORLD. 1º ESO. BILINGUAL TEACHING. Alfonso M. Poza Artés, History and Geography Teacher.

2. SALTWATER AND FRESHWATER IN THE WORLD.

3. WORLD OCEANS ● There are five oceans in the planet earth: ● Arctic Ocean. ● Antarctic Ocean. ● Atlantic Ocean. ● Pacific Ocean. ● Indian Ocean.

4. GREATEST LAKES IN THE WORLD.

5. WATER CYCLE.

6. OCEAN CURRENTS (corrientes marinas).

7. ● Ocean currents are large masses of water circulating in the oceans. ● Depending of its temperature marine currents could be cold or warm. ● Oceans currents affect the climate of the surrounded area. ● A warm current influence in a humid climate and mild temperatures. ● A cold current causes less humidity and therefore desert.

8. TIDES (mareas). ● They are daily ups and downs of sea level. ● They are caused by the attraction of sun and moon on the earth. ● High Tide: when the sea level rises. ● Low Tide: when sea level low.

9. WAVES. ● Waves are ripples of the sea surface caused by wind.

10. RIVERS, SEAS AND OCEANS IN EUROPE.

11. RIVERS.

13. GROUNDWATER.

14. Water Pollution It is caused by human beings, factories, agriculture, ranching, etc. Contamination of rivers, lakes and aquiferous. Contamination in seas and oceans.

15. What are waste waters? It is caused by human activity. Waste waters included the waters from bathrooms, kitchens,washing machines, dumps, etc. Waste waters are responsible of the contamination of rivers, seas and oceans.

16. Waste waters must be treated in specialized water plants before returning this water to the rivers or the sea. In Spain cities with more than 10.000 people must treat waste water.

17. AN ISLAND OF GARBAGE.

19. What is Acid Rain?. It is caused by oxidation of nitrogen and dioxide of sulphur. Factories, electric power stations and petroleum are the responsables for acid rain.

20. These contaminated gases are part of the water in clouds. When it rains, pollution can go to rivers, forests, lakes, seas, etc. When it happens, as in the picture, the contaminated rain can destroy forests.

21. Solutions. Reduce the level of sulphur in fuels. Control the emissions of gases in factories. Reduce the use of carbon and electric power stations to produce electricity. Use hybrid or electric cars. Use public transport like buses, subway or tram.